The compound whose molecules have the highest average kinetic energy is?

C)

Explanation:

The warmer the molecules, the higher the average kinetic energy.

"As stated in the kinetic-molecular theory, the temperature of a substance is related to the average kinetic energy of the particles of that substance. When a substance is heated, some of the absorbed energy is stored within the particles, while some of the energy increases the motion of the particles. This is registered as an increase in the temperature of the substance." -lumen learning

(I know for sure but what think... hope this helped)  

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.

answer; 4 electrons;